Can opener



FIG. 1 is a front elevation of a can opener showing my new design;

FIG. 2 is a right side elevation thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevation thereof;

FIG. 5 is a left side elevation thereof; and

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a can opener, as shown. 